I have recently fitted wind instrument to the top of the mast on my B34- 2000 and there was plenty of room in the second conduit in the mast. There was no spare wiring.

I was lucky though in that I was about to take Tanami on a long cruise to the Whitsundays and as she was eight years old I was advised to have the running rigging renewed. As a result while the mast was lying down I was able to push the wires through with a length of rigging wire.

The best part though that the masthead was a shambles of aluminium rivets and brackets for the antenna and wind indicator. While the mast was down I was able to tap all the fittings so they can be easily unbolted. It would have been impossible to do it up the mast ( I would have dropped half my tools as well).